PC activity tracking

Hamburglar224

Sometimes I shut down my computer, and it turns itself on again while I'm at work. This implies that my roommate turned on my computer, presumably to do something, but I can't figure out what that might be. Yes I could fix the problem by having a password, or I could ask, but that's no fun!

What kind of techniques could I employ to see what went on with my computer while I was away. The internet history is always blank, but was it just deleted? I'd like to know! Was a program run? What time did this occur?

Thanks!

EDIT:
Requirements: Free, windows platform, no malicious code.

Raiden333

Well you could try a keylogger to start out with.

Edit: Started reading a few, this one seems like what you're looking for:

Information in Spector Pro menu is grouped into 11 categories: Screen Snapshots, Chat/IM Activity, Online Searches, Web Sites Visited, Email Activity, Files Transferred, Keystrokes Typed, Program Activity, User Activity, Document Tracking and Keywords Detection, each of which views the corresponding information. It is also possible to see Top 10 of Chat/IM Activity, Online Search, Web Sites Visited, Email Activity, Program Activity and Keywords Detected. All this in addition to a great number of filters makes viewing of intercepted information very comfortable.

The functionality of the program is on a very high level: the program is capable to intercept both sides of chat conversations, all the file activities except opening of the files (it logs all the applications run though), both incoming and outgoing messages, record user logging on and off and its inactivity time. Spector Pro also receives 37 of 42 points for implementing of all the functions from ‘Visual Surveillance’ section, except ‘Ability to choose between full screen and active window screenshots’.

Edit2: Crap, looks like that one doesn't have a free trial, and it's quite pricey. But browse the main site, I'm sure you'll find something. Also, here's a demo of an older version.